My struggle with HP HSTNN-DA25 power adapter

Thread Starter

arishy

Joined Apr 26, 2014
82
I had this power adapter with my high end laptop now scrapped.
The reason I need it is the fact it offers 19 Volt at 6.15 Amp ( very impressive)
What baffled me is the warning on the adapter "Connecting only to grounded output" And since I was using it with HP laptop. I was OK
Now I want to use it as a bench power supply. And my problems escalated.
The adapter provide three wires: White , Blue and Black. ( When I opened the casing there is a wire from the Ground AC source to this wire )
In my case The AC source has no ground Only Live and Neutral. So this black wire is actually floating.
I measured the voltage across Black and White it was +20+ volt
I measured the voltage across Black and Blue it was +20+ volt.

If I connect any of the pairs (Blk/Wt or Blk /blue) to an electronic Load, it goes to zero !!!!!!!

My question to you: How I can use this wonderful Adapter as a NORMAL dc source.
 

thedoc8

Joined Nov 28, 2012
147
Sounds like the adapter is crap, seen quite a few like that. That assumes your load is not a short or close to it. Also with the load connected do you hear any noise out of the supply. What was the problem with the laptop.
 

Thread Starter

arishy

Joined Apr 26, 2014
82
Sounds like the adapter is crap, seen quite a few like that. That assumes your load is not a short or close to it. Also with the load connected do you hear any noise out of the supply. What was the problem with the laptop.
Good point regarding the laptop. It was actually power problem. And since I was in situation that forced me to try to fix it with no service manual; I ended with a dead laptop. The way HP build their laptops, it is impossible to DIY job.

One of the weird things I did ( later I knew why ) is I connected the BLK wire with The Blue wire in attempt to get it working. My surprise was It did not short ( because the Blk wire was floating)
 
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